1. Field of the Invention
The present invention pertains to electrochemical cells for the manufacture of chlorine and caustic soda and the like. More particularly, the present invention pertains to separators or diaphragms for electrochemical cells. Even more particularly, the present invention pertains to thermoplastic fibers for use as separators or diaphragms for electrochemical cells.
2. Prior Art
The manufacture of chlorine and caustic by the electrolytic decomposition of brine in electrochemical cells is well known. Conventionally, the electrochemical cells deploy asbestos diaphragms to separate the anodes and cathodes mounted in the cells. Varying constructions of conventional electrochemical cells are taught in the prior art. See inter alia, U.S. Pat. Nos. 3,312,614; 3,374,164, and Kuhn, Industrial Electrochemical Processes, Elsevier Publishing Co., 1971.
However, as is known to those skilled in the art, the use of asbestos diaphragms have certain inherent disadvantages. Asbestos tends to swell in the presence of the cell liquor which, in turn, results in a reduction of the mechanical strength and gradual wearing out of the diaphragm. Thus, there is the need for constant replacement of asbestos diaphragms which necessitates the closing down of the cell.
The required down time of the cells adds to the cost of operating these electrochemicals cells. Yet, because of the multitude of advantages attendant the use of asbestos diaphragms, they still dominate the field.
Thus, a major advancement would be provided by diaphragms which have all the inherent advantages of asbestos, but which eliminates the disadvantages thereof.